This
movie
shows LCS computed from empirical DPIV data of a piston-cylinder
generated vortex ring. The LCS bound the interior of the vortex. Furthermore, the LCS intersect to form lobes. These lobes dictate which fluid is entrained or detrained over time. A parcel of fluid is placed in the empirically measured flow field. Particles initially inside the red LCS are colored green and those initially located outside are colored black. As time evolves, all black particles
are detrained and all green particles are entrained.

This
animation
shows lobe dynamic structure in the empircally measured flow about a
free-swimming Aurelia aurita jellyfish. The red curve is an LCS computed from the DPIV flowfield. The lobes formed by the LCS bound upstream fluid which is
entrained into the subumbrellar region of the jellyfish, as shown in the movie.